net/vmnet: add vmnet backends to qapi/net

Create separate netdevs for each vmnet operating mode:
- vmnet-host
- vmnet-shared
- vmnet-bridged

Reviewed-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Tested-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Vladislav Yaroshchuk <Vladislav.Yaroshchuk@jetbrains.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

net/vmnet_int.h

@@ -0,0 +1,25 @@
+/*
+ * vmnet_int.h
+ *
+ * Copyright(c) 2022 Vladislav Yaroshchuk <vladislav.yaroshchuk@jetbrains.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+#ifndef VMNET_INT_H
+#define VMNET_INT_H
+
+#include "qemu/osdep.h"
+#include "vmnet_int.h"
+#include "clients.h"
+
+#include <vmnet/vmnet.h>
+
+typedef struct VmnetState {
+  NetClientState nc;
+
+} VmnetState;
+
+
+#endif /* VMNET_INT_H */